Pathology is a medical discipline related to the study and diagnosis of disease. Most frequently pathology involves the analysis and examination of body-fluid, tissue, and cell samples. As a field of general study and research, pathology relates to four aspects of disease: (1) etiology, (2) pathogenesis, (3) morphologic changes, and (4) consequence of morphologic changes.
The field of pathology dates back to Antiquity. Many early societies possessed a rudimentary understanding of biological conditions as a result of dissection/examination. By the Hellenic period of Greece, a causal study of disease had emerged in human culture. Human understanding of disease through pathology continued to advance piecemeal as time progressed; for instance many advances in pathology are attributable to the medieval era of Islam.
However, modern pathology only emerged as a distinct field of study in the late 1800's with the advent of microbiology. Now pathology is a major medical practice that is divided into a number of subdisciplines. In all of these subdisciplines, having a second opinion to check the work of a pathologist is helpful to eliminate erroneous diagnosis. Eliminating diagnostic error in pathology may result in a healthier population and reduce pathologists' exposure to liability.